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Void Formation Analysis in the Molded Underfill Process for Flip-Chip Packaging

Computers, Materials and Continua 2025年第1期84卷 537-551页

作者： Hu, Ian Hung, Tzu-Chun Zhou, Mu-Heng Lin, Heng-Sheng Chen, dao-Long Department of Mold and Die Engineering National Kaohsiung University of Science and Technology Kaohsiung807 Taiwan Product Characterization Corporate R&D Advanced Semiconductor Engineering Inc. Kaohsiung811 Taiwan

Flip-chip technology is widely used in integrated circuit (IC) packaging. Molded underfill transfer molding is the most common process for these products, as the chip and solder bumps must be protected by the encapsulating material to ensure good reliability. Flow-front merging usually occurs during the molding process, and air is then trapped under the chip, which can form voids in the molded product. The void under the chip may cause stability and reliability problems. However, the flow process is unobservable during the transfer molding process. The engineer can only check for voids in the molded product after the process is complete. Previous studies have used fluid visualization experiments and developed computational fluid dynamics simulation tools to investigate this issue. However, a critical gap remains in establishing a comprehensive three-dimensional model that integrates two-phase flow, accurate venting settings, and fluid surface tension for molded underfill void evaluation—validated by experimental fluid visualization. This study aims to address this gap in the existing literature. In this study, a fluid visualization experiment was designed to simulate the transfer molding process, allowing for the observation of flow-front merging and void formation behaviors. For comparison, a three-dimensional mold flow analysis was also performed. It was found that the numerical simulation of the trapped air compression process under the chip was more accurate when considering the capillary force. The effect of design factors is evaluated in this paper. The results show that the most important factors for void size are fluid viscosity, the gap height under the chip, transfer time, contact angle between the fluid and the contact surfaces, and transfer pressure. Specifically, a smaller gap height beneath the chip aggravates void formation, while lower viscosity, extended transfer time, reduced contact angle, and increased transfer pressure are effective in minimizin

关键词： Chip scale packages

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Strategy of preparing SmCo based films with high coercivity and remanence ratio achieved by temperature and chemical optimization

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Journal of rare Earths 2024年第7期42卷 1289-1297,I0004页

作者： Yansong Gong Zhaoguo Qiu Sizhe Liang Xinrui Zheng Hongxia Meng Zhigang Zheng deyang Chen Shengfu Yuan Weixing Xia dechang Zeng J.P.Liu School of Materials Science and Engineering South China University of TechnologyGuangzhou510640China Zhongshan R&D Center for Materials Surface and Thin Films Technology of the South China University of Technology Gent Materials Surface Technology(Guangdong)Co.Ltd.Zhongshan528437China Institute for Advanced Materials South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China Yangjiang Branch Guangdong Laboratory Materials Science and Technology Yangjiang Advanced Alloys LaboratoryYangjiang529500China Laboratory of Rare-Earth Magnetic Functional Materials Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo315201China Department of Physics University of Texas at ArlingtonArlingtonTX76019USA

SmCo based films with excellent intrinsic magnetic properties have promising applications in micro-electro-mechanical system(MEMS).However,due to the complexity of phase composition and uncontrollable crystallization degree of SmCo hard magnetic phase in the film,both the coercivity(Hc)and remanence(Mr)of films are difficult to enhance *** this paper,SmCo based films were deposited with a Cr underlayer and capping layer on single crystal Si substrates via magnetron sputtering *** effects of annealing parameters and Sm/Co atomic ratio on the phase structure and coercivity of films are *** adjusting the Sm/Co atomic ratio from 1:5 to 1:4,Co soft magnetic phase disappears and the single phase SmCo5 is obtained,leading to the increase of coercivity of the films from 30 to 34 *** influence of deposition temperature and Cu doping on magnetic properties of SmCo based films was *** the deposition temperature increases from room temperature to 250℃,the coercivity will further increase from 34 to 51 ***,a severe kink is observed in the demagnetization curves due to the poor exchanged *** analysis of transmission electron microscopy(TEM)confirms that the average size of non-hard magnetic amorphous phase exceeds the effective exchanged coupling length of SmCo5,which contributes to the decoupling and low remanence ***,doping Cu and applying a post-annealing process can significantly improve the crystallization degree of the *** the coercivity and the remanence ratio of the demagnetization curves are greatly *** propose a plausible strategy to prepare the SmCo based films with high coercivity and remanence ratio by temperature and chemical optimization,which can be utilized in high performed MEMS devices.

关键词： rare earths SmCo based films Phase composition Crystallization conditions Coercivity remanence ratio

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Measurement of Absorption Current of Polyester Coated Enameled Wires with Q(t) meter

Measurement of Absorption Current of Polyester Coated Enamel...

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2023 International Symposium on Electrical Insulating Materials, ISEIM 2023

作者： Watanabe, Akinao Fukuma, Masumi Sekiguchi, Yoitsu Advanced Electronic and Information Systems Course National Institute of Technology Matsue College Matsue Japan Department of Electrical Engineering and Computer Science National Institute of Technology Matsue College Matsue Japan Energy and Electronics Materials R&D Laboratories Sumitomo Electric Industries Osaka Japan

ISBN: (纸本)9784886864376

A Q(t) meter is used to measure electrical properties in insulating materials. Here, Q(t) is the integral value of circuit current with time t. It is possible to measure the Q(t) of the insulation material of a capacitor and a cable by using Q(t) meter. The current through an insulating material is divided into an instantaneous charging current, an absorption current and an equilibrium leakage current. It is considered that the absorption current is related to charge accumulation in the insulating materials. In this paper, an enameled wire (1.6 PEW) is used to prepare a cable sample, the Q(t) of the coated polyester (PEs) is measured, and extraction of absorption current components from measured Q(t) are reported. © 2023 The Institute of Electrical Engineers of Japan.

关键词： Insulating materials

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discussion on Instability of Current-controlled Inverter with df/dt-type Virtual Inertia Control

Discussion on Instability of Current-controlled Inverter wit...

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IEEE Energy Conversion Congress and Exposition, ECCE

作者： Takumi Ueda Kenichiro Sano daisuke Terazono Kaho Nada Department of Electrical and Electronic Engineering Institute of Science Tokyo Tokyo Japan Advanced Technology R&D Center Mitsubishi Electric Hyogo Japan

ISBN: (数字)9798350376067

ISBN: (纸本)9798350376074

This paper focuses on the stability of a current-controlled inverter (GFL type) with df/dt-type virtual inertia control. The authors analyze the dynamic characteristics compared to those of synchronous generators and demonstrate the existence of a second-order delay between the electrical frequency and the rotor’s rotational frequency in synchronous generators. Then, this second-order delay is implemented into the df/dt-type virtual inertia control as a second-order low-pass filter (LPF), and the influence of the LPF is investigated by EMT simulation.

关键词： Simulation Low-pass filters Power system stability Synchronous generators Inverters Stability analysis delays Frequency synchronization Voltage control Frequency control

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reduction of Carrier Harmonic Iron Loss of Phase-Shift Windings dual Three-Phase Motors by Phase Current-Shift Control

Reduction of Carrier Harmonic Iron Loss of Phase-Shift Windi...

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International Conference on Electrical Machines and Systems (ICEMS)

作者： Yoshihiro Miyama Kan Akatsu Advanced Technology R&D Center Mitsubishi Electric Corporation Amagasaki Japan Department of Faculty of Engineering Yokohama National University Yokohama Japan

ISBN: (数字)9784886864406

ISBN: (纸本)9798350379105

A carrier harmonic iron loss reduction technique for the phase-shift windings dual three-phase motors is proposed in this manuscript. By controlling two three-phase current phase-shifts from 30 degrees to -30 degrees, the voltage phase-shift is controlled from 30 degrees to 19 degrees, and the first and third carrier harmonic iron loss is reduced to a 42.9% maximum. Finite element analysis (FEA) confirms that the carrier harmonic current and carrier harmonic iron loss is reduced related to carrier harmonic impedance.

关键词： Torque Windings Harmonic analysis Motors Iron Finite element analysis Impedance Copper Voltage control

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Novel Temporary Bonding/debonding System Enabling advanced Packaging Process

Novel Temporary Bonding/Debonding System Enabling Advanced P...

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International Conference on Electronics Packaging (ICEP)

作者： Emi Miyazawa Tetsuya Enomoto Yuta Akasu Shogo Sobue Yuki Nakamura Saeko Ogawa Takashi Kawamori High Performance Materials Department Packaging Materials Group Institute for Advanced Integrated Technology Resonac Corporation Packaging Materials R&D Department Film R&D Group Electronics R&D Center Electronics Business Headquarters Resonac Corporation High Performance Materials Department Bonding Materials Group Institute for Advanced Integrated Technology Resonac Corporation

Novel temporary bonding/debonding system including high heat resistant temporary bonding adhesive and debonding methods with newly developed photonic release by Xe flash light irradiation will be introduced. New temporary bonding adhesive is endurable up to 300 °C and can be easily removed by peeling off after debonding from the support carrier. By adopting the dual layer structure with adhesive layer and metal layer on glass carrier, one-shot Xe flash light irradiation within 5 ms enables debonding cleanly, indicating the increased throughput at debonding step. Process demonstration results of wafer thinning down to 50 μm, fan-out wafer level packaging (FOWLP) will also be shown.

关键词： resistance radiation effects Xenon Packaging Throughput Wafer scale integration reliability

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Near-infrared-emitting (Gd1-yNdy)3(Ga1-xCrx)5O12 glass ceramic phosphors for light-emitting diodes

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Ceramics International 2025年第16期51卷 22488-22497页

作者： Chen, Yu-Chen Li, Po-Yu Kung, Chung-Wei Chang, Jhe-Wei Kao, Cheng-Wei Kuo, Chi-Ching Liu, Wei-ren Department of Chemical Engineering Chung Yuan Christian University R&D Center for Membrane Technology Center for Circular Economy 200 Chung Pei Rood Chungli District Taoyuan City32023 Taiwan Department of Molecular Science and Engineering Institute of Organic and Polymeric Materials National Taipei University of Technology Taipei106 Taiwan Department of Chemical Engineering National Cheng Kung University Tainan City70101 Taiwan National Synchrotron Radiation Research Center Hsinchu30076 Taiwan Advanced Research Center for Green Materials Science and Technology National Taiwan University Taipei10617 Taiwan

In this study, we proposed a blue-excitable and near-infrared (NIr) emission ceramic phosphor - Gd3Ga5O12:Cr3+, Nd3+ (GGO:Cr, Nd) by a solid-state reaction for light-emitting diode applications. The as-synthesized Gd3Ga4.95Cr0.05O12 phosphor displayed a broad emission peak at 759 nm (4T2 → 4A2) with a full-width-half-maximum of 122 nm under 460 nm excitation. In order to generate NIr, we introduced Nd3+ ions as activators to substitute Gd3+ ions in GGO:Cr3+ phosphors. Via energy transfer from Cr3+ ions to Nd3+ ions in GGO, an intense NIr emission at 1064 nm resulting from 4F3/2 → 4I11/2 is demonstrated. Furthermore, we investigate the doping effects at various concentrations and reanalyzed the luminescent characteristics of (Gd1-yNdy)3(Ga1-xCrx)5O12 phosphors to determine the optimal doping concentration of Cr and Ni, which were found to be 1 mol.% and 3 mol.%, respectively. Finally, we mix the composition-optimized (Gd0.97Nd0.03)3(Ga0.99Cr0.01)5O12 NIr-emission phosphor with silica-based glass powder. After cold pressing and high-temperature sintering using molds, we obtain NIr-emitting glass-ceramic phosphors through laser cutting technology and packaged them into high-power light-emitting diodes. © 2024 Elsevier Ltd and Techna Group S.r.l.

关键词： Glass ceramics

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Mechanical Properties and Thermal Shock resistance of SrAl_(2)Si_(2)O_(8) reinforced BN Ceramic Composites

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无机材料学报 2024年第10期39卷 1182-1188页

作者： WANG Bo CAI delong ZHU Qishuai LI daxin YANG Zhihua dUAN Xiaoming LI Yanan WANG Xuan JIA dechang ZHOU Yu International Joint Laboratory of Advanced Nanomaterials of Heilongjiang Province College of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Key Laboratory of Advanced Structural-Functional Integration Materials School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China China Resources Cement Technology R&D Co. LtdGuangzhou 510000China The First Military Representative Office of the Army Equipment Department in Beijing Beijing 100072China The Fourth System Design Department Fourth AcademyChina Aerospace Science and Industry Corporation LimitedBeijing 100048China School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

Hexagonal boron nitride(h-BN)ceramics have become exceptional materials for heat-resistant components in hypersonic vehicles,owing to their superior thermal stability and excellent dielectric ***,their densification during sintering still poses challenges for researchers,and their mechanical properties are rather *** this study,SrAl_(2)Si_(2)O_(8)(SAS),with low melting point and high strength,was introduced into the h-BN ceramics to facilitate the sintering and reinforce the strength and ***,BN-SAS ceramic composites were fabricated via hot press sintering using h-BN,SrCO_(3),Al_(2)O_(3),and SiO_(2) as raw materials,and effects of sintering pressure on their microstructure,mechanical property,and thermal property were *** thermal shock resistance of BN-SAS ceramic composites was *** show that phases of as-preparedBN-SAS ceramic composites are h-BN and h-SrAl_(2)Si_(2)O_(8).With the increase of sintering pressure,the composites’densities increase,and the mechanical properties shew a rising trend followed by a slight *** a sintering pressure of 20 MPa,their bending strength and fracture toughness are(138±4)MPa and(1.84±0.05)MPa·m^(1/2),*** sintered at 10 MPa exhibit a low coefficient of thermal expansion,with an average of 2.96×10^(-6) K^(-1) in the temperature range from 200 to 1200℃.The BN-SAS ceramic composites prepared at 20 MPa display higher thermal conductivity from 12.42 to 28.42 W·m^(-1)·K^(-1) within the temperature range from room temperature to 1000℃.Notably,BN-SAS composites exhibit remarkable thermal shock resistance,with residual bending strength peaking and subsequently declining sharply under a thermal shock temperature difference ranging from 600 to 1400℃.The maximum residual bending strength is recorded at a temperature difference of 800℃,with a residual strength retention rate of 101%.As the thermal shock temperature difference increase,the degree of oxida

关键词： BN matrix composite hot-press sintering mechanical property thermal shock resistance service reliability

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Effect of Ca addition on the microstructure and mechanical properties of heat-treated Mg-6.0Zn-1.2Y-0.7Zr alloy

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Journal of Magnesium and Alloys 2021年第5期9卷 1636-1648页

作者： Young Gil Jung Wonseok Yang Yong Joo Kim Shae.K.Kim Young Ok Yoon Hyunkyu Lim do Hyang Kim Advanced Materials and Process R&D Department Korea Institute of Industrial Technology156Gaetbeol-roIncheon 21999Republic of Korea Department of Metallurgical Engineering Yonsei University50Yonsei-roSeoulSeodaemun-gu 03722Republic of Korea

In this study,the effects of Ca addition on the microstructure,thermal properties,and mechanical properties of a Mg-6.0Zn-1.2Y-0.7Zr(ZWK611)alloy at room temperature and 150℃ were *** an increase in the Ca content,the ignition resistance of the ZWK611 alloy improved and the grains became *** as-cast ZWK611 alloy consisted mainly of the dendriticα-Mg matrix and I-phase(Mg_(3)Zn_(6)Y)at the grain *** the other hand,theτ-(Ca_(2)Mg_(6)Zn_(3))and I-phases were formed in the Ca-added ZWK611 *** fraction of theτ-phase increased with an increase in the Ca *** the solid-solution treatment,these phases remained partially at the grain boundaries of the Ca-added ZWK611 alloys and an additional W-phase(Mg_(3)Zn_(3)Y)was *** phases remaining at the grain boundaries restricted the grain growth through the grain boundary pinning *** aging treatment resulted in the formation of MgZn'precipitates in theα-Mg matrix of the *** precipitates were more uniformly distributed in the Ca-added alloys than in the alloys without ***,the heat treatment-induced precipitation improved the tensile and creep properties of the T6-treated *** T6-treated ZWK611+0.7Ca alloy exhibited the best mechanical properties at room temperature and 150℃ among all the tested alloys.

关键词： Mg-Zn-Y alloys Heat-treatment Precipitate Mechanical properties Thermal analysis

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Predictive Maintenance in IoT Networks Using a Temporal Attention Mechanism Based Federated Convolutional Neural Network 4

Predictive Maintenance in IoT Networks Using a Temporal Atte...

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4th IEEE Asian Conference on Innovation in technology, ASIANCON 2024

作者： Guduri, Naga Venkata ramakrishna Charaan, r.M. dilip Kalaiyarasi, r. Samuthira Pandi, V. reddy, d.Laxma Selvaprabhu, T. University of Technology and Applied Sciences Faculty of Engineering Al Musannah Oman Vel Tech Rangarajan Dr.Sagunthala R&d Institute of Science and Technology Department of Computer Science and Engineering Tamil Nadu Chennai India Rajalakshmi Institute of Technology Department of Artificial Intelligence and Data Science Tamil Nadu Chennai India Chennai Institute of Technology Centre for Advanced Wireless Integrated Technology Tamil Nadu Chennai India Mlr Institute of Technology Department of Ece Hyderabad India Dhanalakshmi College of Engineering Department of Cse Tamil Nadu Chennai India

ISBN: (纸本)9798350354218

In the era of Industry 4.0, edge devices in industrial settings generate vast amounts of data crucial for process optimization and Predictive Maintenance (PM). Traditional cloud-based approaches for handling this data are becoming untenable due to cost, latency, and privacy issues. Federated learning emerges as a viable solution, offering localized and efficient data processing while mitigating these challenges. This paper presents a Federated Convolutional Neural Network with Temporal Attention Mechanism (FedCNN-TAM) for PM tasks in Internet of Things (IoT) networks. This model leverages temporal features in sensor data to enhance predictive accuracy. Evaluated on the CMAPSS dataset, FedCNN-TAM outperforms representative models with a significant performance gain. This model exhibits the potential for broader applications in industrial IoT, setting the stage for future research on its scalability and adaptability to multi-modal data types. © 2024 IEEE.

关键词： Spatio-temporal data

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